Abstract: The need to rehabilitate dams without draining their valuable reservoirs is impacting the way the Bureau of Reclamation makes modifications. There are no two better examples of this than the $200 million worth of rehabilitations planned for Theodore Roosevelt and Stewart Mountain dams. Major reservoir drawdowns were avoided—creative solutions had to be implemented. The height of Theodore Roosevelt Dam will be raised by 77 ft and a new power generating turbine will be installed. More than 60 post-tensioned cables will be used to strengthen Stewart Mountain Dam. This is believed to be one of the first ever applications of post-tensioned cables to stabilize an arch dam. The dams, both located east of Phoenix, are part of the Salt River Project that was originally authorized in 1908. Theodore Roosevelt Dam, which remains the tallest masonry dam in the world, was completed in 1911. Stewart Mountain Dam, a thin concrete arch structure located downstream from Theodore Roosevelt Dam, was completed in 1930.